Global Warning To Cause Historic 'Megadrought' In American West, Researchers Predict

Global warning might bring the historic 'megadrought' in Southwest and Great Plains, according to a new study.

The study contrasts sharply with the recent assessments that report greater uncertainty about future droughts. Researchers used historic tree ring data and three drought measure. They concluded that there was at least 80 percent chance of a 35-year-long drought that could occur by the end of this century.

"Imagine a naturally occurring drought, such as the one occurring in California ... imagine that going on for decades ... that's kind of a mega-drought," said lead study author Benjamin Cook, a climatologist at NASA Goddard Institute for Space Studies.

According to many experts, California's current drought is the result of natural climate variability and not the result of global warning.

"Even at the middle-of-the-road scenario, we see enough warming and drying to push us past the worst droughts experienced in the region since the medieval era," Cook added.

Cook's team also used 17 computer models of droughts and three models of soil moisture to predict the likelihood of dryness over the next century.

"Even when selecting for the worst megadrought-dominated period, the 21st-century projections make the megadroughts seem like quaint walks through the Garden of Eden," study co-author Jason E. Smerdon of Columbia University's Lamont-Doherty Earth Observatory said in a statement.

Researchers added that the future drought risk will probably exceed that of the Medival Anomaly.

"Our results point to a remarkably drier future that falls far outside the contemporary experience of natural and human systems in Western North America, conditions that may present a substantial challenge to adaptation," the authors wrote.

"Human populations in this region, and their associated water resource demands, have been increasing rapidly in recent decades, and these trends are expected to continue for years to come."

The forecast was published online in the journal Science.